1. Field of the Invention
The present invention relates to a semiconductor integrated circuit having a test circuit and more specifically to collecting test data associated with an internal function based on data received from an external source via a communication circuit.
2. Description of Related Art
A microcomputer is normally provided with a test mode as one of potentially many modes of operation. The typical conventional test mode is used to execute a test program for testing circuit functions of the microcomputer. For example, as described in JP-1993-36904 A, the use of serial communication for collecting or configuring data associated with a test is known.
Generally, the serial communication is used to collect data from a communication destination as follows. The communication destination receives communication data containing a command that requests data collection. The destination collects data stored in a targeted circuit at the time the command is received or thereabouts and returns the data. Basically, the communication destination can only collect data stored in the targeted circuit at the time when the command is received and at no other time. Accordingly, it is difficult or impossible in such a conventional situation to collect data generated at various times other than the time when the command is received.